1. Field of the invention
The present invention relates to a steering column for a vehicle. More specifically, the present invention relates to a steering column for a vehicle that can: easily adjust the collapse load of the steering column in case of a collision of the vehicle; improve collision performance by adjusting the collapse load in conformity with the collision property according to the type of vehicle; and reduce the number of components, the assembly process, and the assembly cost.
2. Description of the Prior Art
Steering columns for vehicles generally include a telescopic function and a tilt function, and drivers can adjust the degree to which the steering wheels protrude and the angles by which the steering wheels are tilted in conformity with their heights or body types to effectively perform steering operations.
FIG. 1 is a perspective view of a steering column for a vehicle according to the related art.
As illustrated in FIG. 1, the steering column for a vehicle, according to the related art, includes: a steering shaft 101 connected to the steering wheel (not illustrated) of the vehicle; a column housing 103 that surrounds the steering shaft 101; a sliding housing 105 inserted into the column housing 103 to slide in the axial direction; a nut fixing part 107 formed on the rear end of the sliding housing 105; a telescope nut 117 that is coupled to the outer peripheral portion of the nut fixing part 107 and has a female screw formed on the inner circumferential surface thereof; a telescope motor 111 provided on a side of the column housing 103; a worm shaft 113 driven by the telescope motor 111; a telescope screw 109 that has a worm wheel 115 formed on the front end thereof and engaged with the worm shaft 113 and a male screw formed on the rear end thereof and inserted into the telescope nut 117; and a tilt housing 133 tilted about a hinge shaft 135 by a tilt motor 131 and a tilt screw 137.
The steering shaft 101 is connected at the upper end thereof to the steering wheel (not illustrated) and rotates according to a driver's operation of the steering wheel (not illustrated) to transmit a steering force to both wheels (not illustrated) through a rack and pinion mechanism (not illustrated) at the lower end thereof.
The steering wheel 101 has a structure in which upper and lower steering shafts 101a and 101b are configured to slide relative to each other so that a telescopic operation is possible.
The column housing 103 is formed to surround the steering shaft 101 and is secured to the body of a vehicle through upper and lower brackets 121 and 123 formed on the upper and lower sides thereof, respectively, to support the steering shaft 101.
The sliding housing 105 surrounds the steering shaft 101 and is inserted into the upper end of the column housing 103 so as to slide relative to the column housing 103. The sliding housing 105 has a cylindrical shape and is coupled, at the rear end thereof, to the nut fixing part 107.
The telescope nut 117 moves forward or backward in the axial direction according to the rotation of the telescope screw 109 to make the telescopic operation possible. The telescope nut 117 is press-fit into the outer peripheral portion of the nut fixing part 107 and extends in the axial direction of the column housing 103.
Meanwhile, the nut fixing part 107 includes a coupling pin 110 that simultaneously passes through the telescope nut 117 and the nut fixing part 107.
Since the coupling pin 119 is not completely secured to the telescope nut 117 or the nut fixing part 107 even though the coupling pin passes through the telescope nut 117 and the nut fixing part 107, the telescope nut 117 may rotate about the coupling pin 119 at a predetermined angle and may also move upward and downward by a predetermined distance along the coupling pin 119.
The worm shaft 113 is rotated by a driving force received from the telescope motor 111 to drive the telescope screw 109.
The telescope screw 109 is driven by the telescope motor 111 and the worm shaft 113 to allow the telescope nut 117 and the nut fixing part 107 to move forward and backward.
When the driver operates a telescope switch (not illustrated), the motor is driven, and the driving force of the motor is transmitted to the telescope screw 109 through the worm shaft 113 and the worm wheel 115 to rotate the telescope screw 109 so that the sliding housing 105 to which the telescope nut 117 is coupled slides in the direction of the steering shaft, thereby performing a telescopic function.
However, as described above, the steering column for a vehicle, according to the related art, has a structural problem in that a primary collision energy absorbing component, such as a capsule 121a coupled to the upper bracket 121, and a secondary collision energy absorbing component, such as a tearing plate (not illustrated), are separately required, and the number of components and working processes increase in order to separately manufacture and assemble the collision energy absorbing components.
Furthermore, a method of absorbing impact using the fracture of a tearing groove, which forms a groove having a predetermined depth, when the tearing plate secondarily absorbs a load after the capsule primarily absorbs a load has a problem in that manufacturing the product is complex, and deformation is vertically caused, which generates a lateral load deviation due to an interference with surrounding components.